Gas compressor



Dec. 24, 1935. c. A. BERGMANN GAS COMPRESSOR Original Filed Aug. 2, 1935 2 Sheets-Sheet 1 INVENTOR.

ATTORNEYS Dec. 24, 1935. Q BERGMANN 2,025,037

GAS COMPRESSOR Original Filed Aug. 2, 1933 Z-Sheeps-Sheet 2 INVENTOR.

'4 ATTORNEY.

Patented Dec. 24, 1935 GAS COMPRESSOR Carl A. Bergmann, Milwaukee, Wis., assignor to Walter D. Mann, Milwaukee, Wis.

Application August 2, 1933, Serial No. 683,332 Renewed April 15, 1935 20 Claims.

for compressing air or other elastic fluids with the aid of centrifugal force acting upon a carrier liquid.

Generally defined, an object of the invention is to provide improved apparatus for producing high compression of gases in a substantially isothermal manner and with maximum efficiency.

While it has heretofore been proposed to utilize an ordinary centrifugal pump for the purpose of hydraulically compressing air to some extent, by mixing the air with the liquid passing through the pump rotor and by subsequently separating the air from the mixture expelled by the rotor, this. method of compression is relatively inefiicient and is not adapted for high compression of the gas.

It is a more specific object of the present invention to provide an improved rotary hydraulic compressor for elastic fluids such as air, wherein any desired degree of compression of the gas may be obtained with minimum expenditure of power, by utilizing centrifugal force to compress the fluid while mixed with liquid, and by additionally utilizing the pressure acting upon the separated liquid to regain the energy which is substantially wasted when utilizing the ordinary centrifugal pump for air compression purposes.

Another specific object of the invention is to provide a rotary hydraulic air compressor of relatively simple and compact construction adapted to produce substantially isothermic compression of gas to relatively high pressures in a single stage.

A further specific object of the invention is to provide an improved rotary gas compressor which is relatively devoid of leakage and friction losses, and which is especially adapted for use in con- 'nection with refrigeration systems and in conjunction with rotary motors such as gas turbines.

Still another specific object of the invention is to provide an improved high compression rotary gas compressor which is entirely automatic and continuous in its operation, and wherein the fluent compressing media is repeatedly re-utilized and retained at desired temperature.

Another specific object of the invention is to provide a simple rotary hydraulic compressor which is adapted to effectively simultaneously compress several different kinds of elastic fluid, and wherein centripetal force acting upon the gas carrier is utilized to enhance the compression.

These and other objects and advantages will be apparent from the following detailed description.

A clear conception of several embodiments and adaptations of the invention, and of the mode of constructing and of operating rotary hydraulic compressors in order to carry on the improved method, may be had by referring to the drawings accompanying and forming a part of this specification in which like reference characters designate the same or similar parts in the various vlews.

Fig. 1 is a somewhat diagrammatic central 1ongitudinal section through one form of the improved rotary hydraulic air compressor and through the control mechanism thereof;

Fig. 2 is a transverse section through the rotor of the compressor of Fig. l, the section having been taken along the line 22;

Fig. 3 is an enlarged fragmentary circumferential section through the liquid discharge portion of the rotor of Fig. 1, taken along the line 3-3;

' Fig. 4 is a central longitudinal section through a modified form of structure for admitting the gas and for mixing the same with the liquid compressing medium to initially compress the gas before entering the rotor;

Fig. 5 is a central longitudinal section through a fragment of a modified rotor adapted to simul- 1 taneously compress segregated charges of the same or different kinds of gas;

Fig. 6 is a diagrammatic central longitudinal section through a further modified form of rotor embodying a different type of energy regaining apparatus cooperating with the separated gas carrier liquid;

Fig. '7 is a diagrammatic transverse section taken centrally through the modified rotor of Fig. 6; and

Fig. 8 is a relatively diagrammatic elevation of a rotor of Figs. 6 and '7, showing a velocity diagram of the discharged gas carrier liquid.

Referring specificallyv to Figs. 1, 2 and 3, the improved gas compressor therein disclosed, comprises in general a frame IS, a casing l9 cooperating with the frame I8 to provide a sealed chamber, a rotor disposed within the chamber, a shaft 2| to one end of which the rotor 20 is attached, a bearing housing 22 secured to the frame l8 and rotatably supporting the shaft 2|, and a pulley 23 or equivalent means for imparting rotation to the shaft 2| and rotor 20.

The rotor 20 is provided with a series of substantially radial compression conduits 24 having sion conduits 24. This construction provides compression conduits 24 which are of greater radial length than the corresponding return conduits 21, and the passages in the return casing28 are formed to deliver the returned liquid centrally into the nozzle 25, thus completing the liquid circuits within the compressor. The liquid return casing 28 supports an air or other gas supply housinghaving a central inlet opening controlled by a non-return check valve 29, and gas admission ducts 3E) connect the supply housing with the ,.-space within the normally fixed nozzle 25. The .,nozzle 25 is constantly urged along the rotor axis andinto sealing engagement with an annular abutment on'the return casing 28, by one or more springs 3| but may be moved in opposition to the spring by gas under pressure, and the peripheral portion of the rotor 20 is provided with annular 'gas collecting grooves 32 which communicate with all of the separating conduits 26 on both sides of the radial conduits 24, 2'1.

Compressed'gas discharge ducts 33, formed within the rotor 20, have their outer ends communicable with the grooves 32 and controllable by means of valves 34 whichare operable by floats 35,- and the inner ends of the ducts 33 are in open communication with one end of a centralgas discharge passage 36 formed in the rotor shaft 2|. 'Theopposite end of the passage 36 is connected to a chamber 31, through radial holes in the shaft 2|, the chamber 3'! being disposed adjacentto g anti friction bearings 38 carried within the housing 22 and coacting withthe shaft 2|.

The ends of the chamber 31 are sealed by packings 39, and a discharge pipe 46 connects this chamber with another chamber 4| in one end of a tank 42, a non-return check valve 43 being interposed between the chamber 31 and the pipe 40. The tank -chamber 4| is provided with a final compressed V gas outlet having a pressure retaining discharge qvalve 44 therein, and is also provided with a safety pressure-relief Valve 45. A pipe 46 connects the tank chamber 4| with a port in the liquid return casing 28 adjacent to the end flange of the nozzle 25, and a control valve 41 is inter- I posed in the pipe 46 for the purpose of regulating the axial movement of the nozzle 25 in opposition, The valve 41 is operable by the fluid pressure from Within the chamber 4| actto the spring 3|.

ing upon a plunger 48 in opposition to a spring 49, and has a pressure relief port 50 which connects the nozzle 25 ,withthe atmosphere when the pressure within the chamber 4| is abnormally low. As the pressure within the chamber 4| reaches its maximum, the pressure acting upon,

the plunger 48 will position control valve 41 to permit gas under pressure to flow through the pipe 46 to the duct adjoining theactuating flange of the inlet nozzle 25, and the nozzle is subjected to pressure sufficient to overcome the pressure exerted by the spring 3|, and the nozzle is shifted 1 to the right as viewed in Fig. 1 to thereby throttle the inlet to the compression-conduits'u.

The tank 42 is also provided with a liquid storage reservoir having a float actuated valve 52 which discharges the excess liquid accumulating during operation of the compressor, and a drain cook 53 associated with the lower portion thereof, and a screen or filter wall 54 segregates these 7 elements from the outlet pipe 55 which leads from the reservoir 5| to the compressor rotor inlet. The chamber formed by the'frame I8 and casing l9, and surrounding the rotor, is connected to the interior of the reservoir 5| in line with the =inlet of the pipe 55, by a pipe 56, thus creating anejector effect and establishing a partial vacuum around the exterior of the rotor 20. A branch pipe 51 connects a medial portion of the vacuum producing pipe 56 with a sealing chamber 58 surrounding the hub of the rotor 26, thus expelling leakage liquid which may escape from the rotor inlet passages, before it enters the space surrounding the rotor. The reservoir 5| is also provided with a safety valve 58' which is set at a. comparatively low pressure, just sufiicient to force the water into the rotor for priming purposes, and to maintain the circulation of the cooling water, an air pump 59, and with a liquid intake valve 60, and is of sufficient capacity to hold all of the liquid normally filling the rotor and sufficient excess to insure proper'operation of the system.

. The liquid return passage within the. return casing 28 is connected by means of a pipe 6| to theupper portion of a radiator 62, the radiating tubes of which are disposed around-the bearing housing 22, and the lower portion of the radiator communicates through a pipe 63 with thereservoir 5| in. advance of a bafile wall 64 as shown in Fig. 1. The capacity of the pipe 6| is relatively limited, and the heated liquid Withdrawn by this pipe, is cooled in the radiator and flows through the pipe 63 to the reservoir 5| by gravity and due ,to the kinetic energy of the liquid in the return casing 28. In order to enhance the cooling effect,

,.the radiator 62 may be subjected to a circulation of air from a fan 65 mounted upon the shaft 2| 1 Within a conduit 66 carried by the radiator, and

the fan 65 cooperates with a centrifugal governor 66 which in turn coacts with a slide valve 61 to cut off communication between the high pressure gas chamber 4| and the reservoir 5| when the unit is at rest. The valve 61 is interposed 5 between ducts 68, 69, the former of which communicates with the chamber 4| and the latter of which leads to a diaphragm actuated slide valve .16, and another duct 'II connects the valve 10 directly with the upper'portion of the reservoir 5|. The valve 10 is operable by a diaphragm I2, one side of which is exposed to the pressure in the reservoir 5| through a pipe 13,'and the opposite side of which is connected to the return passage within the casing28, by a pipe", so that if the pressures in the reservoir are sufilcient to force the liquid into the compressor, the valve 10 will be shifted to cut off communication between the ducts 69,-1l.

., During normal operation of the improvedro- 5 tary compressor shown in Figs. 1, 2 and 3, rotary motion is-imparted to the rotor 20 with the aid of the pulley 23 attached to the shaft 2|, and the liquid within the rotor 20 and casing 28 is being constantly circulated through the conduits 24, 26, 70 21 at velocities dependent upon the speed of revolution ofthe rotor. As this liquid passes through the stationary return passages in the casing 28 and flows through the relatively fixed, nozzle 25,

air or other gas is entrained through the ducts 311v and past the valve 29, and is mixed with the liquid in the form of bubbles as shown in Figs. 1 and 2. In passing outwardly through the compression conduits 24, the columns of mixture are subjected toprogressively increasing centrifugal force, and when the separating conduits 253 are reached the air or gas under high pressure is expelled from the liquid by the continued action of centrifugal force thereon, and enters the annular passages 32 from whence it flows through the passages 33, 38 into the chamber 31 and eventually escapes to the chamber t! through the pipe 40. The separated liquid flows into the return conduits 21 by virtue of the-lesser head of liquid in these conduits and the resultant decreased centrifugal force acting upon the return columns, and the difference in head of the columns in the conduits 2d and 2? is sufficient to overcome the friction of the liquid flowing through the rotor. The pressure and the peripheral speed of the particles of the liquid are reduced while they return through conduits 2'5. The kinetic energy of the liquid which is consumed by the particles of the liquid passing through conduits 24 where they gradually reach the maximum peripheral speed in the conduits 25, is returned in conduits El. It is evident that the circulating liquid does not consume any power, because the wall pressures which accelerate and decelerate the liquid while flowing through the rotor cancel each other.

The liquid conduits 2'! within the rotor hub adjacent to the casing 28 are preferably formed as shown in Fig. 3, in order to reduce the absolute speed of the returning liquid in the casing 23, to approximately the intake speed of the liquid in the rotor, and to eliminate eddy currents. The degree of compression is obviously dependent upon the speed of the rotor 29, and the compressed gas may be withdrawn from the chamber 4| past the discharge valve 44.

The heat generated during the compression of the gas, is quickly absorbed by the carrier liquid thereby maintaining the compression substan tially isothermic. Due to the absorption of the heat of compression by the liquid, this liquid upon entering the passages within the casing 28 will be heated, and in order to maintain the carrier liquid at substantially uniform temperature, a portion thereof is permitted to pass into the radiator 62 through the pipe 65. The revolving fan 65 cools the liquid entering the'radiator 62, and this cool liquid is subsequently delivered to the reservoir 5| from whence it is eventually returned to the casing 28 where it is mixed with the warmer return liquid passing into the nozzle 25. The radiator 62 may obviously be utilized for heating purposes, in large compressors where the volume of liquid is suflicient to warrant such use, thus conserving the heat for useful purposes. The liquid returned through the pipe 55, besides cooling the liquid within the rotor 2 also sets up an ejector action which produces a partial vacuum within the casing l9 and surrounding the rotor, thereby reducing to a minimum the friction losses; and if so desired, the fan 65 may be omitted thus further reducing the power required to drive the compressor.

If the pressure within the chamber M accidentally becomes excessive, the safety valve A5 will function to automatically release the excess pressure. When the compressor is at rest the valve 41 will be shifted by the spring 49, to bring the duct adjoining the actuating flange of the inlet nozzle 25 into communication with the atmosphere through the port 50, and the spring 3| will shift the inlet nozzle 25 to the left. Another spring will shift the slide valve 10 so as to connect the duct 69 with the duct H. The centrifugal governor 6% Will be at rest, thereby causing the slide valve El to disconnect the duct 69 with the chamber il through the duct 68, so that leakage is prevented from the chamber 4 I and a slight pressure is always retained within this chamber by valve 4 for priming purposes, after the compressor has once been operated.

In order to prime the unit when the compressor is started, the pump 59 may be operated to establish suiiicient pressure within the reservoir 5| above the liquid therein, to properly fill the rotor conduits 24, 26, 21 through the pipe 55. The 15 floats 35 ccacting with the valves 34, will maintain the ducts 33 sealed until gas under pressure lodges in the gas passages 32, whereupon these floats 35 will ride upon the liquid flowing through the conduits 26 within which these floats are dis- 9; posed. After the compressor has once been started due to the rotation of the rotor 20 and shaft 2 l, the governor 66 will open valve Bl, thus allowing gas to escape from within the reservoir 41 through slide valve l0 into the reservoir 5 I This gas presses on the liquid in the reservoir 5! and forces this liquid into the compressor which is thus primed; and after the rotor has once been primed, the entire operation and control is automatic. The periphery of the rotor 20 may also be 0 provided with automatic drain plugs as shown in Fig. 2, in order to permit removal of all liquid from the rotor so as to prevent possible freezing when the machine is idle.

Referring specifically to Fig. 4, the mixture 5 supply nozzle '55 of this modification, differs from the nozzle 25 of Figs. 1, 2 and 3, in that it is formed integral with the liquid return casing 76 and has an expanding or enlarging cross-section in the direction of flow of the gas and liquid mixture. 40 The rotor 25) is of the same construction as previously described, and the operation of this modified machine is similar to that previously described, with the exception that the gas is precompressed as it passes through the expanding 45 nozzles l5, where velocity energy of the mixture is changed into pressure energy, thus making possible a higher ratio of gas to liquid for the mixture. This structure is also simpler than that previously described, by virtue of the inte- 50 gral construction of the nozzle 15 and return casing 16.

Referring specifically to the double rotor structure of Fig. 5, this construction is more especially adapted for machines of larger capacities, or 55 in machines wherein it is desired to simultaneously compress segregated charges of different kinds of gas which are to be ultimately mixed with each other. In this machine, the rotor 11 is provided with two sets of substantially radial 60 compression conduits 18, and with two sets of cooperating liquid return conduits F9, and with intervening axially extending separating conduits 8 connecting the outer ends of the corresponding compression and return conduits l8, 19. All of the annular separating conduits 80 of each set, communicate with an annular compressed gas collecting duct Bi, and the ducts 80 insure a perfect balancing of the rotor. In case one compression conduit discharges more liquid 70 than the other conduits, the annular level of the liquid is quickly equalized by the centrifugal force and the balance of the rotor is not destroyed. The ducts 8i communicate with a common gas discharge passage 82 which connects with a disand the operation of this double compressor should be apparent from the foregoing description. While the axial disposition of the liquid separating conduits 80, somewhat increases the width of the rotor, over the previously described circumferential arrangement thereof, this axial -arrangement will permit more comp-act disposition of the other conduits 18, I9 and is therefore especially suitable for a double compression machine.

' Referring specifically to the machine illustrated in Figs. 6 to 8 inclusive, this compressor differs from those previously described, in the mode of regaining the energy of the carrier liquid after the'compressed gas has been liberated. The rotor 85 is supported by a shaft-86 and is provided with substantially radial compression conduits 81 the inner ends of which communicate with a gas and liquid supply nozzle 88, and the outer ends of which are connected to an annular liquid separating conduit'89 communicating with an annular compressed air collecting passage 90. The rotor 85 is housed within a sealed casing 9! having a liquid storage reservoir -92 therebeneath and communicating with the space within the casing 9| surrounding the rotor, through ports 93. The lower end of the nozzle 88 is in open communication with the reservoir 92 beneath the level of the liquid therein, and the gas to be compressed is supplied to the nozzle 88 by ducts 94, while the compressed gas is discharged from the passage 85 through ducts 95, 96 and a final discharge pipe 91. In this modified machine, the return of the separated carrier liquid is effected by delivering the same from the separating duct 89 through tangential nozzles 98, and the reaction of the jets of liquid delivered at high velocity from the nozzles 98 during rotation of the rotor 85,.serves to simultaneously difiuse the pressure on the carrier liquid so as to augment the compression of the compressed gas, and to assist in driving the rotor 85, thereby reducing the energy losses to a minimum. The relative speed W of the liquid is nearly opposed to the peripheral speed U of the rotor and is only slightly smaller than speed U, so that the energy is negligible in the liquid which leaves the rotor with the small absolute velocity C. The liquid is discharged by the nozzles 93 through the ports 93 and creates a partial vacuum in the space within the easing 9! due to the ejector action of the jets. In this machine, as in those previously described, the compression is effected by centrifugal force acting upon the liquid columns within the conduits 81, and the separation of the liquid and gas is likewise effected by centrifugal force within the same rotor.

From the foregoing description of the various modifications, it will be apparent that the invention provides a simple, compact and highly efiicient gas compressor wherein the actual compression and separation of the gases under pressure is effected with the aid of centrifugal force within a single rotor. The deceleration or diffusion of the carrier liquid is utilized in various Ways to augment the gas compression, and the compressed gas is always delivered from the machine in relatively dry condition. The compression is substantially. isothermic, and minimum power is required by operating the compressor rotorin a partiarvacuum. 'The heat resulting from the compression may also beutilized "for heating or other purposes, thereby reducing the energy losses to a minimum, and the improved method has proven highly satisfactory in actual use.

duit, means for removing compressed gas from said rotornear the other end of said conduit,'g means associated with said rotor for decelerating the flow of the separated liquid and for causing said deceleration to augment the compression of the gas, and means operable by the generated pressure for controlling boththe maxie mum and the minimum pressures obtainable.

2.-In a compressor, a rotor having therein a compression conduit extending away from themtor axis, means for delivering a mixture of liquid and gas into a portion of said conduit ad.- jacent said axis, means for causing the mixture to travel within said rotor and laterally of said conduit near the outer end thereof to separate the compressed gas from the liquid, means for decelerating the flow of the separated liquid with- 5 in said rotor to augment the pressure of the removed gas, means for automatically controlling the maximum pressure obtainable, and means for automatically controlling the minimum pressure obtainable.

3. In a compressor, a rotor having therein a compression conduit extending away from the rotor axis, means for delivering a mixture of-liquid and gas into a portion of said conduit adjacent said axis, means for causing the mixture to travel within said rotor and laterally of said conduit near the outer end thereof to separate the compressed gas from the liquid, means for decelerating the flow of the separated liquid within said rotor to augment the pressure of the removed gas, means for directly returning the diffused liquid to the inlet portion of said conduit, and a non-return check valve associated with said liquid return means for permitting ingress of liquid while preventing escape of liquid.

4. In a compressor, a rotor having therein segregated substantially radial compression and return conduits connected by a conduit all portions of which are-disposed substantially equidistant from the rotor axis, means for admitting a mixture of gas and liquid to the end of said compression conduit adjacent the rotor axis, means including a float controlled valve for effecting removal of compressed gas from the side of said connecting conduit nearest said axis, and means for returning liquid from the end of said return conduit adjacent said axis to the'corresponding end of said compression conduit.

5. In a compressor, a rotor having therein an outwardly directed compression conduit and an inwardly directed return conduit of less length than said compression conduit, means for admitting mixed gas and liquid to the inner end of said compression conduit, means for removingflzs compressed gas from the outerend of said compression conduit and for delivering the separated liquid into the outer end of said return conduit, means for delivering said liquid from the opposite end of said return conduit into the corresponding end of said compression conduit together'with other gas, and means for automatically discharging excess liquid from the compression and return passages.

6. In a compressor, a rotor having therein a conduit for receiving a mixture of liquid and gas and for utilizing centrifugal force to compress the gas, float controlled means for eiiecting discharge of compressed gas from said conduit, a housing for said rotor, and means for utilizing the action of one of the fluids to maintain the interior of said housing under reduced pressure.

7. In a compressor, a rotor having therein a conduit for receiving a mixture of liquid and gas and for utilizing centrifugal force to compress the gas, a casing forming a chamber surrounding said rotor, and means for utilizing the action of one of the fluids to maintain said chamber under a partial vacuum.

8'. In a compressor, a rotor having therein an outwardly directed conduit for compressing gas mixed with liquid flowing outwardly through said conduit, means forming a gradually expanding passage for admitting the liquid to the inner end portion of said conduit, means for introducing gas into said passage in pre-compressed condition, and means for pre-cooling the liquid circulated through said passage.

9. In a compressor, a rotor having therein a plurality of compression conduits extending away from the rotor axis, means for delivering a mixture of liquid and gas in pre-cooled condition to the inner end portion of each of said conduits, fioat controlled means for removing compressed gas near theouter end of each of said conduits, and independent means associated with said rotor for decelerating the flow of the separated liquid discharged from each of said conduits.

10. In a compressor, a rotorhaving therein a plurality of compression conduits extending away from the rotor axis, means for delivering mixed gas and liquid into the inner end portion of each of said conduits, means forming separating conduits within said rotor extending along the axis thereof and away from the outer ends of said compression conduits, means for independently conducting gas and liquid away from said separating conduits, a liquid supply reservoir, and means for pneumatically delivering liquid from said reservoir to said rotor for priming purposes.

11. In a compressor, a rotor having therein a compression conduit extending away from the rotor axis, means for delivering mixed gas and liquid into the end portion of said conduit adjacent to said axis, means forming a separating conduit extending around said axis, and means for discharging the separated liquid from said rotor into the ambient atmosphere tangentially of the rotor periphery.

12. In a compressor, a rotor having a compression conduit extending away from the rotor axis, means for delivering a mixture of liquid and gas to the inner end portion of said conduit, means for removing compressed gas from said rotor near the outer end of said conduit, means associated with said rotor for decelerating the flow of the separated liquid and for causing said deceleration to augment the compression of the gas, and means for releasing excess gas pressure from Within said rotor and for, preventingaccumulation of excess gas in said gas removing means.

13. In a compressor, a rotor having a compression conduit extending away from the rotor axis,

means for delivering a mixture of liquid and gas 5 to the inner end portion of said conduit, means for removing compressed gas from said rotor near the other end of said conduit, and a safety valve for releasing excess pressure and for preventing accumulation of excess air in said gas removing means.

14. In a compressor, a rotor having therein a plurality of compression conduits extending away from the rotor axis, means for delivering mixed gas and liquid into the inner end portion of each of said conduits, means forming separating conduits within said rotor for removing the gas from the liquid in said mixture, means for independently conducting gas and liquid away from said separating conduits, a reservoir for receiving gas 20 from said rotor, and means for utilizing the pressure of the gas within said reservoir for priming said rotor.

15. In a compressor, a rotor having therein a plurality of compression conduits extending away 25 from the rotor axis, means for delivering mixed gas and liquid into the inner end portion of each of said conduits, means forming a common separating conduit within said rotor communicating with the outer ends of all of said compression 30 conduits, and means for independently conducting gas and liquid away from said separating conduit.

16. In a compressor, a rotor having therein a plurality of compression conduits extending away 35 from the rotor axis, means for delivering mixed gas and liquid into the inner end portion of each of said conduits, means forming a common separating conduit within said rotor communicating with the outer ends of all of said compression conduits, means for independently conducting gas and liquid away from said separating conduit, and common means for removing liquid from all of said conduits and from said liquid conducting means.

17. In a compressor, a rotor having therein a plurality of compression conduits extending away from the rotor axis, means for delivering mixed gas and liquid into the inner end portion of each of said conduits, means forming a common separating conduit within said rotor communicating with the outer ends of all of said compression conduits, means for independently conducting gas and liquid away from said separating conduit, and float actuated means for controlling the delivery of gas from said separating conduit to said gas conducting means.

18. In a compressor, a rotor having therein a compression conduit extending outwardly away from the rotor axis, means for delivering 60 mixed gas and liquid into the end portion of said conduit adjacent to said axis, means forming a separating conduit extending from the outer end of said compression conduit around said axis, means for conducting compressed gas from said 65 separating conduit toward the axis of said rotor, and means for freely discharging the separated liquid from said rotor into the ambient atmosphere tangentially of the rotor periphery.

19. In a compressor, a rotor having therein an outwardly directed conduit for compressing gas mixed with liquid flowing outwardly through said conduit, means forming a gradually expanding passage for admitting the liquid directly to the inner end portion of the conduit, means for introducing gas into said passage in'pre-com end-portion of saidconduit; float controlled means pressed condition, and meansfor varying the point of admission of said gas with respect-to said' expanding passage.

-'. "20. In a compressor, a rotor-having an outwardly directed compression conduit, means for delivering a mixture of liquidand gas to the inner for' removing compressed gas 'from the liquid-nearer theouter'end'o'f said'conduit, and meansfor re-L turning the separated liquid to the inner end of 1 said compression conduit together with additional 8 gas to be compressed.

CARL A. BERGMANNJ 

